Ventilator



UNITED STATES P TENT OFFICE.

CHRISTIAN A. FREDERIGKS, OF BROOKLYN, NEW YORK.

'VENTIJLATOR.

SPEGJQFICATION forming part oi Letters Patent No. 248,092, dated October 11, 1881.

Application filed May 19, 1881. (Model) To all whom it may concern:

Be it known that I, CHRISTIAN A.FREDER1 IoKs, a citizen of the United States, residing in Brooklyn, Kings county, New York, have invented certain Improvements in Ventilators,

generally employ a motor-wheel fixed to the same shaft with the exhaust-fan and exceeding the latter in diameter. These Ifind to answer very well for small shafts where both fan and wheel are of small size, but for larger shafts they are entirely inadequate. The reason for this lies in the fact that the peripheral speed of the motor-wheel is never greater than the speed of the wind, and with a given velocity of the air-current the angular velocity will be inversely as the diameter of the motor-wheel.

:Heretofore, so far as I am aware, such ventilators have been constructed after one model, or in one proportion, for all sizes of shafts, and whenever it was necessary to increase the diameter of the exhaust-fanthe motor-wheel was likewise increased in diameter. In following this method I found that in constructing the ventilator described in my Patent No. 240,245, of April 19, 1881, it would do good work when made on a small scale, but was useless when triedon alarger scale, by reason of the low angular velocity of the motor-wheel in light winds. Consequently when a wheel of larger diameter is employed for the purpose of insuring blade-surface and leverage enoughto rotate a large exhaust-fan it will be found that the fan willnot have speed enough-to exhaust the air unless the velocity of the wind be exceptionally great.

to give the fan the proper speed to enable it I this, or .nearly so, no .matter how much the diameterof the fan maybe increased, to suit large ventilating-shafts. Then,to get the requisite blade-surface to give the motor-wheel power to rotate the fan efi'ectually with alight wind, I extend said motor-wheel axially. Thus, in enlarging the ventilator it will be seen that I enlarge thefan diametrically and the motorwheel axially,while the diameter of themotorwheel and the axial measurement of the fanare not materially altered. As the fan is enlarged diametrically, the angular velocity remaining constant, its peripheral velocity will be increased,and this will increase its effectiveness somewhat; but the work itwill be required to performwill also be increased in acorre'sponding ratio, sothat, with a given angular velocity, the conditions will remain about the same, however much the diameter may be increased.

' In the drawings which serve to illustrate my invention, Figurel is a vertical sectional el'evation of myimproved ventilator, the rotative parts being in elevation and the stationary parts in midsection. Fig. 2 is a sectional plan of the same on the line 2 2 in Fig. 1. Fig. 3 is a vertical mid-sectional view, illustrating a modification of my improved ventilator.

The approved'mode of carrying out my invention is illustrated in Figs. 1 and 2, wherein A is an ordinary ventilating-shaft, over the top ofwhich is mounted an ordinary exhaust-fan, B, on an arbor or axis, 0. Over the fanis fixed-a capor roof,*l) which is connected with the ventilating-shaft by means of a conical band or hOllSillgfE, preferably of sheet metal -or similar material. The object of this band or shield is to prevent the wind from acting injurionsly upon the exhaust-fan, and at :the same time permit the escape of the air ex hausted by the fan, as indicated by the arrows.

--locity,- andthiscannot be obtained, lithe-tan is large, through a motor-wheel having'a diameter equal or nearly equal to that of the fan and fixed to the same shaft in the usual way; and ifa wheel of less diameter be employed for the purpose of insuring sufficient angular velocity the leverage and blade-surface will be reduced so much that it will not have power to rotate the fan.

To obviate the difficulty I employ, by preference, a motor-wheel, F, mounted on theprolongation ofthe axis 0. This wheel is reduced in diameter sufficiently to give the required angular velocity to the fan with a light wind, and elongated axially to obtain sufficient bladesurfaee for the wind to act upomwhereby power to rotate the fan is obtained. In other words, the effective working power of the motor-wheel is not disturbed, while its angular velocity is increased to the desired extent by reducing its diameter.

For large ventilators, and to these alone, I propose to apply my improvements. The diameter of the fan will always be greatly in excess of that of the motorwheel, and the axial measurement ofthe motor-wheel will always greatly exceed that of its diameter, and this disparity will always increase with the size of the ventilator.

To lessen the friction at the bearings ot the axis 0 its upper end is provided with a bearing-block, a, of metaline, so called, fixed in a plate or spider, I), supported on brace-rods The lower end of the axis is of steel, hardened and pointed, and the joint rests in a slight indentation in a hardened-steel plate or disk, 0?, which rests on the end of an adjustingscrew, 0. This screw forms the bottom of a socket, f, in a spider fixed in the ventilatingshaft.

I have found that where glass bearings are employed ashes and grit will get into the bearings and cut them out. If steel is used it will rust out in a short time unless protected. To effect the necessary protection, I form the receptacle or socket f around the bearing-point and fill this with powdered plumbago or black lead. This prevents the grit or ashes from getting at the bearing, and also prevents oxidation of theparts. In lieu of plumbago powdered steatite or other similar anti-friction material may be employed.

By reference most particularly to Fig. 2 it will be seen that the blades of the motor-wheel are attached tangentially to the shaft or arbor, and curved or bent so as to oppose a concave face to the wind. This tangential arrangement of the blades has the effect to enlarge the useful area exposed to the wind, as best indicated by the broken arrows in Fig.2, which show the direction of the wind, and how it is deflected by the tangential attachment of the blades. This curvature of the blades of the motor-wheel I employ by preference; but I may employ plane or fiat blades with good results, provided the other conditions of the construction of the motonwheel are adhered tothat is to say, if the blades be extended axially to get blade-surface enough to compensate for reduced diameter.

Where the fan is very large and the upward extension or elongation of the motor-wheel would heexccssive, the modification illustrated in Fig. 3 might be employed. In this construction the motor-wheel is cut into four short sections, each mounted in separate bearings. On the lower ends of their arbors are fixed gear-wheels a a, which mesh with a gearwheel, I), on the fan-arbor. By this construction the joint effect of the motor-wheels is to rotate the fan. This construction is equivalent to one long motor wheel cut into several lengths, and each applied independently to assist in rotating the fan.

The flange 1' around the margin of the shaft A may be perforated, if desired, to prevent the collection of moisture in cold weather, which is liable to freeze and clog the fan. The shield E may or may not be of foraminous material.

I am aware that a motor-wheel having a diameter a little less than the exhaust-fan has been shown in ventilators; but the disparity in diametrical measurement has not been such as would materially affect the operation of the device, and such constructions have doubtless been limited to small ventilating-shafts. Such a construction is shown in the patent of A. P. Blake, dated January 31, 1865, No. 46,067, and I hereby disclaim the subject-matter of said patent.

Having thus described my invention, I claim- 1. The combination, to form a ventilating apparatus, of an exhaust-fan mounted at the top of the shaft, and a wind motor-wheel above and on the same shaft or arbor with the fan, the said fan having a diameter much greater than that of the'motor-wheel, and the said motor-wheel being axially extended sufficiently to give it a blade area or surface greater than that of the fan, substantially as and for the purposes set forth.

2. The combination, to form aventilating apparatus, of a centrifugal exhaust-fan arranged at the top of the ventilating-shaft, and a windmotor wheel above and on the same shaft or arbor with the fan, the said fan having a diameter much greater than that of the motorwheel, and the motor-wheel having an axial measurement greater than its diametrical measurement, substantially as and for the purposes set forth.

3. Aventilatin g apparatus comprisinga centrifugal exhaust-fan arranged over the top of the ventilating-shaft, as shown, a cap or roof for the fan, a wind-motor wheel over the roof arranged to rotate the fan, and a shield, E, arranged around the fan to protect it against the force of the wind, but so as to leave ample space above and below for the escape of the air and gases expelled by the fan, substantially as and for the purposes set forth.

4.. A motor-wheel for actuating the fan of a ventilatorhavin g an axial measurement greatly exceeding its diametrical measurement, and its blades bent intoa curved form and attached to the arbor or shaft tangentially, whereby great angular velocity is obtained without loss of power, substantially as set forth.

5'. An apparatus capable of ventilatin g large shafts when actuatedonly by light winds, comprisingacentrifu gal exhaust-fan arranged over the top of the'shaft and adapted to be rotated, and a wind -motor wheel above the fan and mounted on the same arbor, said motor-wheel having a diameter much less than that of the fan, and an axial measurement greater than its diametrical measurement,and havingits blades curved, as shown, and secured tangentially to its arbor, snbstantiall y as and for the purposes set forth.

6. The combination, to form a bearing for the pointed arbor of ventilating'fan, of the socketed spider orsupport, the hardened plate or disk 01, to bear up the arbor, the adjusting-screw e, and the filling in the socketf, substantially as set forth.

7. A hearing for the'arbor of a ventilating"- 2 5 fan, which comprises a cup-like socket with a hardened-steel plate or diskat its bottom, having a slight indentation to receive the pointed tip of the arbor, and afillin g of powdered plumbago in the said socket around the'arbor to 0 protect the latter and the bearing-plate from oxidation and foreign abrasive substances, substantially as set forth. "x

In witness whereof I have hereunto signed my name in the presence of two subscribing 5 witnesses.

CHRISTIAN A. FREDERIOKS. Witnesses:

HENRY GoNNETT, ARTHUR O. FRASER. 

